It also will be much more: a crucial test of whether America can remain, as Abraham Lincoln said, “the last best hope of earth.” That, in turn, makes it an important 90 minutes for the world.

Americans like to believe ― and have reason to believe ― that they are a force for freedom and dignity. They think they invented modern concepts of human rights, self-determination and representative government in the 18th century; that they won the fight against totalitarianism in World War II and the Cold War in the 20th; that they and others have tried to spread a humane democratic capitalism in the 21st.

So what is the world to make of a “last best hope of earth” that is now tempted ― seriously tempted ― to turn its destiny over to a vain, ethically challenged real estate developer and TV star?

Here is a man who is proud of his ignorance, untethered to truth, bereft of government experience, cynical about the law, dismissive of longtime allies in NATO and East Asia, admiring of world dictators, prone to racist remarks, allied with ultra-conservative grassroots groups and as bellicose as a street boxer.

Having defeated totalitarianism and communism, will the U.S. now validate a xenophobic, racist personality cult driven by fame and social media?

Will there be an American “strongman?”

It’s a global trend, after all, led by the likes of Vladimir Putin in Russia, Xi Jinping in China, Narendra Modi in India and a host of lesser dictatorial figures, among them Kim Jong Un in North Korea, Rodrigo Duterte in the Philippines and Nicolás Maduro in Venezuela.

How did we get to this place, with a strongman having a chance to kick in the door?

In what has become a close race with Democratic presidential nominee Hillary Clinton, the same trait that made Trump attractive to agitated and suspicious Republicans is now holding him back: his reckless willingness to unleash the racial and ethnic fears that flow like a poisoned river through the American landscape.

Cunning and adaptable ― a master of using media to sell his “brand,” which is himself ― Trump is capable of acting “presidential.” Expectations for Trump are so low that if he remains calm and reasonable, and demonstrates even a morsel of knowledge about the issues, he’ll be judged the winner by those in the media who see the contest as a mere horserace.

If Trump behaves disruptively on purpose, loses his cool, overdoes his attacks on Clinton (the first woman to head a major ticket), lies even more conspicuously than he has so far, or displays a particularly abject lack of knowledge ― his chances, one would think, will diminish.

There are two more debates after Monday, but interest and audience ― and impact ― tend to fade after the first one.

How did we get to this place, with a strongman having a chance to kick in the door?

Americans voters are in a particularly gloomy mood, for one, saying by a 2-to-1 margin that the country is “on the wrong track.”

And no wonder. For the past two years, in parallel with the presidential campaign, the American news media has been full of stories of mass death and social division: deadly attacks by ISIS-inspired terrorists, police shootings of unarmed African-Americans; Black Lives Matter demonstrations from coast to coast.

Voters don’t like their choices this election; indeed, Trump and Clinton are two of the least popular nominees to face each other in modern times. The corrosive political atmosphere favors anger over the appeal of experience ― in other words, it favors Trump over Clinton.

Trump’s “America First” mantra is alluring in a country where the resentment of “others” and disdain for the world ― immigrants, economic competitors, “nation building” ― is rampant.

The parties are also becoming ever more divided in demographic terms. Trump’s supporters are overwhelmingly male and white in a country where the electorate remains about 70 percent white. Clinton is drawing more than 95 percent support among blacks, more than 80 percent among Latinos and strong support from educated Americans.

But it’s hard for the party that controls the White House for two terms to win a third election in a row. That’s happened only once since World War II, in 1988, when Vice President George H.W. Bush succeeded Ronald Reagan by defeating Democrat Mike Dukakis.